Field of the Invention
The present invention relates to a method of transmitting and receiving video contents, and more particularly, to a method of transmitting MMT-packaged video contents through a plurality of transmission networks.
Discussion of the Related Art
After standardization of MPEG-2, new video compression standards (or audio compression standards) such as MPEG-4, H.264/AVC, and scalable video coding (SVC) have continually been developed, and each new standard has formed a new market, thereby widening the utilization area of MPEG standard. However, transmission technologies such as MPEG-2 transport system (TS) have been widely used in a digital broadcast, a mobile broadcast (T-DMB, DVB-H, etc.), etc. for about 20 years without a significant change, and even the technologies are widely used in multimedia transmission through Internet, i.e., IPTV service.
However, the multimedia transmission environment at the time when MPEG-2 TS was developed and the today's multimedia transmission environment are going through significant changes. For example, MPEG-2 TS standard was developed at that time in consideration of transmitting multimedia data through the ATM network, but today, it is difficult to find an example which is used for this purpose. Further, requirements of multimedia transmission by using Internet, etc. were not considered at the time of making MPEG-2 TS standard, and thus there are elements which are not efficient in multimedia transmission through Internet. Hence, the establishment of MPEG Media Transport layer (MMT) which considers the multimedia service in Internet which fits a changing multimedia environment is being considered as a very important subject.
Likewise, an important reason why the MMT standardization is performed is that the MPEG2-TS standard, which was made 20 years ago, is not optimized for the recent IPTV broadcast service, Internet, environment, etc., and thus the MMT is standardized as a new transmission technology standard in the MPEG by an urgent need of the optimized multimedia transmission international standard in the multimedia transmission environment in recent various heterogeneous networks.
Further, the multimedia contents services are being generalized on the basis of the video in the convergence environment of communication and broadcasting along with the high speed of the wireless network and Internet. In the convergence environment for contents consumption where terminals of various performances such as a smartphone and a tablet PC are mixed as well as the existing TV or PC, services, which allow the seamless use of the video, music, game, and data, are called N-screen services.
In such various terminals, contents of various resolutions, which fit each terminal, are consumed, and as a mobile service becomes available, the contents consumption environment which changes the network environment in real time is being made. In order to provide high-quality contents which fit the consumption environment which changes in real time, the existing video encoding scheme which supports a single format is not sufficient.
In this respect, a study on scalable video coding (SVC) is in active progress. The SVC has been designed to allow real time adaptation to various transmission environments and terminal performance. That is, this is a video encoding scheme which allows real time adaptation which supports a format which fits a variable heterogeneous consumption environment such as the resolution and network state which are various required according to the terminal.
As described above, SVC video contents, which may provide appropriate video contents adaptively according to various terminal performances and the changing network environment, and a plurality of transmission networks may be utilized when transmitting such SVC video contents through various heterogeneous networks in MMT scheme.